1. Field of the Invention
This invention relates to compositions of matter comprising a pesticidal organothiophosphorus compound and a particulate clay carrier in admixture with a polyalkylene glycol and an acid which provide pesticidal compositions of high storage stability and which compositions are useful, among other pesticide controls, for highly effective control of corn rootworm.
2. Description of the Prior Art
Glycols have been previously used to stabilize organothiophosphorus compounds such as phosphorodithioates and phosphorodithioites when mixed with certain clay carriers, and it is also known to deactivate acid sites on various clay carriers or diluents for insecticidal compositions. For example, U.S. Pat. No. 2,970,080 relates to the use of certain polyalkylene (e.g., ethylene) glycols to stabilize some insecticidal compositions containing organic phosphates (e.g., phosphorodithioates). U.S. Pat. No. 2,868,688 relates to the use of nitrogeneous compounds (e.g., ammonium carbamate, urea, etc.) to deactivate acid sites on such clay carriers. The prior art also discloses the use of acids as deactivators of clay carriers; Sankyo-Japanese No. 62/15,648 relates to the use of fatty acids (e.g., C.sub.14 -C.sub.18) to stabilize organophosphorus insecticides; S. Goto, I. Muta, R. Sato, Botyu-Kagaku 24-93108 (1959) also disclose such use of fatty acids.
J. A. Polon & E. W. Sawyer, J. Ag. Food Chem. 10-244 (1962) discuss the use of acid stabilizing agents to decrease the decomposition of such organophosphorus compounds as Malathion on high-sorptive clay carriers; also discussed is the use of glycols for similar purposes. However, no reference known to applicant discloses or teaches the joint use of glycols and acids as disclosed herein to stabilize organothiophosphorus compounds admixed with clay carriers.